The association of cigarette smoking and alcohol drinking with body mass index: a cross-sectional, population-based study among Chinese adult male twins

Table 4 Moderating effects of cigarette smoking and alcohol drinking on variance components of BMI^a

	Additive genetic modification		Common environment modification		Unique environment modification
	β_a	95 % CI	β_c	95 % CI	β_e	95 % CI
Moderate to heavy cigarette smoking	−0.044	(−0.126 0.040)	0.127	(0.004 0.253)	0.014	(−0.005 0.033)
Current alcohol drinking	−0.137	(−0.215 -0.058)	0.187	(0.077 0.302)	−0.005	(−0.023 0.014)

β_a: Moderating effect on additive genetic component; β_c: Moderating effect on common environment component; β_e: Moderating effect on unique environment component;
Abbreviations: CI confidence interval, BMI body mass index
^aAdjusted for age and region in the model

ISSN: 1471-2458